In recent years, although various types of portable telephones having various functions are provided, their parts are often immature partly. In particular, concerning an opening/closing structure for a portable telephone, although currently most popular folding structures (see FIG. 8A) had very original shapes when they were first introduced, they are currently similar and may be rather banal. In view of this, the manufacturers are searching for a surprising opening/closing structure that differentiates their portable telephones from those of their competitors. For example, a slide structure as shown in FIG. 8B and a T-shape hinge structure as shown in FIG. 8C have been proposed.
As the slide structure, for example, Japanese Patent Laid-Open No. 2004-229049 discloses a portable terminal comprising an upper housing 101 and lower housing 102 that are slidable with respect to each other. This portable terminal can take either a closed state in which the upper housing 101 and lower housing 102 entirely overlap with each other, and an open state in which the upper housing 101 is slid with respect to the lower housing 102.
As the hinge structure, for example, Japanese Patent Laid-Open No. 2004-187185 discloses a foldable portable device having a hinge unit 203 which connects a first unit 201 and second unit 202 to be relatively openable/closeable about an opening/closing shaft as the center and relatively rotatable about a fixed shaft perpendicular to the opening/closing shaft as the center.